I'm enjoying everything about the WiFi Body Scale that Withings sent me -- except for the number that shows up when I step on it (but that's not their fault). This scale wirelessly sends my weight, fat mass, and BMI to a personal web page at Withings.com and to my Google Health page, my RunKeeper account, and my DailyBurn account.
To set it up, I connected it to my computer with a USB cable and filled out some information online. The USB port is hidden in the scale's battery compartment because you only have to use the cable once. After that, all I have to do is step on the scale. There are no buttons or on-off switch. It's a very nice looking, solid-feeling gadget, that does one thing and does it flawlessly. It's a great device for self trackers.